1 /*
2  * Copyright 2017 Google Inc.
3  *
4  * Use of this source code is governed by a BSD-style license that can be
5  * found in the LICENSE file.
6  */
7 
8 #include "GrBackendTextureImageGenerator.h"
9 #include "GrContext.h"
10 #include "GrContextPriv.h"
11 #include "GrGpu.h"
12 #include "GrProxyProvider.h"
13 #include "GrRenderTargetContext.h"
14 #include "GrResourceCache.h"
15 #include "GrResourceProvider.h"
16 #include "GrResourceProviderPriv.h"
17 #include "GrSemaphore.h"
18 #include "GrTexture.h"
19 #include "GrTexturePriv.h"
20 #include "GrTextureProxyPriv.h"
21 #include "SkGr.h"
22 #include "SkMessageBus.h"
23 #include "gl/GrGLTexture.h"
24 
25 GrBackendTextureImageGenerator::RefHelper::~RefHelper() {
26     SkASSERT(nullptr == fBorrowedTexture);
27 
28     // Generator has been freed, and no one is borrowing the texture. Notify the original cache
29     // that it can free the last ref, so it happens on the correct thread.
30     GrGpuResourceFreedMessage msg { fOriginalTexture, fOwningContextID };
31     SkMessageBus<GrGpuResourceFreedMessage>::Post(msg);
32 }
33 
34 std::unique_ptr<SkImageGenerator>
35 GrBackendTextureImageGenerator::Make(sk_sp<GrTexture> texture, GrSurfaceOrigin origin,
36                                      sk_sp<GrSemaphore> semaphore, SkColorType colorType,
37                                      SkAlphaType alphaType, sk_sp<SkColorSpace> colorSpace) {
38     GrContext* context = texture->getContext();
39 
40     // Attach our texture to this context's resource cache. This ensures that deletion will happen
41     // in the correct thread/context. This adds the only ref to the texture that will persist from
42     // this point. That ref will be released when the generator's RefHelper is freed.
43     context->contextPriv().getResourceCache()->insertCrossContextGpuResource(texture.get());
44 
45     GrBackendTexture backendTexture = texture->getBackendTexture();
46     GrBackendFormat backendFormat = backendTexture.getBackendFormat();
47     if (!backendFormat.isValid()) {
48         return nullptr;
49     }
50     backendTexture.fConfig =
51             context->contextPriv().caps()->getConfigFromBackendFormat(backendFormat, colorType);
52     if (backendTexture.fConfig == kUnknown_GrPixelConfig) {
53         return nullptr;
54     }
55 
56     SkImageInfo info = SkImageInfo::Make(texture->width(), texture->height(), colorType, alphaType,
57                                          std::move(colorSpace));
58     return std::unique_ptr<SkImageGenerator>(new GrBackendTextureImageGenerator(
59           info, texture.get(), origin, context->contextPriv().contextID(),
60           std::move(semaphore), backendTexture));
61 }
62 
63 GrBackendTextureImageGenerator::GrBackendTextureImageGenerator(const SkImageInfo& info,
64                                                                GrTexture* texture,
65                                                                GrSurfaceOrigin origin,
66                                                                uint32_t owningContextID,
67                                                                sk_sp<GrSemaphore> semaphore,
68                                                                const GrBackendTexture& backendTex)
69     : INHERITED(info)
70     , fRefHelper(new RefHelper(texture, owningContextID))
71     , fSemaphore(std::move(semaphore))
72     , fBackendTexture(backendTex)
73     , fConfig(backendTex.config())
74     , fSurfaceOrigin(origin) { }
75 
76 GrBackendTextureImageGenerator::~GrBackendTextureImageGenerator() {
77     fRefHelper->unref();
78 }
79 
80 ///////////////////////////////////////////////////////////////////////////////////////////////////
81 
82 void GrBackendTextureImageGenerator::ReleaseRefHelper_TextureReleaseProc(void* ctx) {
83     RefHelper* refHelper = static_cast<RefHelper*>(ctx);
84     SkASSERT(refHelper);
85 
86     refHelper->fBorrowedTexture = nullptr;
87     refHelper->fBorrowingContextReleaseProc = nullptr;
88     refHelper->fBorrowingContextID = SK_InvalidGenID;
89     refHelper->unref();
90 }
91 
92 sk_sp<GrTextureProxy> GrBackendTextureImageGenerator::onGenerateTexture(
93         GrContext* context, const SkImageInfo& info, const SkIPoint& origin, bool willNeedMipMaps) {
94     SkASSERT(context);
95 
96     if (context->backend() != fBackendTexture.backend()) {
97         return nullptr;
98     }
99     if (info.colorType() != this->getInfo().colorType()) {
100         return nullptr;
101     }
102 
103     auto proxyProvider = context->contextPriv().proxyProvider();
104 
105     fBorrowingMutex.acquire();
106     sk_sp<GrReleaseProcHelper> releaseProcHelper;
107     if (SK_InvalidGenID != fRefHelper->fBorrowingContextID) {
108         if (fRefHelper->fBorrowingContextID != context->contextPriv().contextID()) {
109             fBorrowingMutex.release();
110             return nullptr;
111         } else {
112             SkASSERT(fRefHelper->fBorrowingContextReleaseProc);
113             // Ref the release proc to be held by the proxy we make below
114             releaseProcHelper = sk_ref_sp(fRefHelper->fBorrowingContextReleaseProc);
115         }
116     } else {
117         SkASSERT(!fRefHelper->fBorrowingContextReleaseProc);
118         // The ref we add to fRefHelper here will be passed into and owned by the
119         // GrReleaseProcHelper.
120         fRefHelper->ref();
121         releaseProcHelper.reset(new GrReleaseProcHelper(ReleaseRefHelper_TextureReleaseProc,
122                                                         fRefHelper));
123         fRefHelper->fBorrowingContextReleaseProc = releaseProcHelper.get();
124     }
125     fRefHelper->fBorrowingContextID = context->contextPriv().contextID();
126     fBorrowingMutex.release();
127 
128     SkASSERT(fRefHelper->fBorrowingContextID == context->contextPriv().contextID());
129 
130     GrSurfaceDesc desc;
131     desc.fWidth = fBackendTexture.width();
132     desc.fHeight = fBackendTexture.height();
133     desc.fConfig = fConfig;
134     GrMipMapped mipMapped = fBackendTexture.hasMipMaps() ? GrMipMapped::kYes : GrMipMapped::kNo;
135 
136     // Must make copies of member variables to capture in the lambda since this image generator may
137     // be deleted before we actuallly execute the lambda.
138     sk_sp<GrSemaphore> semaphore = fSemaphore;
139     GrBackendTexture backendTexture = fBackendTexture;
140     RefHelper* refHelper = fRefHelper;
141 
142     GrBackendFormat format = backendTexture.getBackendFormat();
143     SkASSERT(format.isValid());
144 
145     sk_sp<GrTextureProxy> proxy = proxyProvider->createLazyProxy(
146             [refHelper, releaseProcHelper, semaphore,
147              backendTexture](GrResourceProvider* resourceProvider) {
148                 if (!resourceProvider) {
149                     return sk_sp<GrTexture>();
150                 }
151 
152                 if (semaphore) {
153                     resourceProvider->priv().gpu()->waitSemaphore(semaphore);
154                 }
155 
156                 sk_sp<GrTexture> tex;
157                 if (refHelper->fBorrowedTexture) {
158                     // If a client re-draws the same image multiple times, the texture we return
159                     // will be cached and re-used. If they draw a subset, though, we may be
160                     // re-called. In that case, we want to re-use the borrowed texture we've
161                     // previously created.
162                     tex = sk_ref_sp(refHelper->fBorrowedTexture);
163                     SkASSERT(tex);
164                 } else {
165                     // We just gained access to the texture. If we're on the original context, we
166                     // could use the original texture, but we'd have no way of detecting that it's
167                     // no longer in-use. So we always make a wrapped copy, where the release proc
168                     // informs us that the context is done with it. This is unfortunate - we'll have
169                     // two texture objects referencing the same GPU object. However, no client can
170                     // ever see the original texture, so this should be safe.
171                     // We make the texture uncacheable so that the release proc is called ASAP.
172                     tex = resourceProvider->wrapBackendTexture(
173                             backendTexture, kBorrow_GrWrapOwnership, GrWrapCacheable::kNo,
174                             kRead_GrIOType);
175                     if (!tex) {
176                         return sk_sp<GrTexture>();
177                     }
178                     refHelper->fBorrowedTexture = tex.get();
179 
180                     tex->setRelease(releaseProcHelper);
181                 }
182 
183                 return tex;
184             },
185             format, desc, fSurfaceOrigin, mipMapped, GrInternalSurfaceFlags::kReadOnly,
186             SkBackingFit::kExact, SkBudgeted::kNo);
187 
188     if (!proxy) {
189         return nullptr;
190     }
191 
192     if (0 == origin.fX && 0 == origin.fY &&
193         info.width() == fBackendTexture.width() && info.height() == fBackendTexture.height() &&
194         (!willNeedMipMaps || GrMipMapped::kYes == proxy->mipMapped())) {
195         // If the caller wants the entire texture and we have the correct mip support, we're done
196         return proxy;
197     } else {
198         // Otherwise, make a copy of the requested subset. Make sure our temporary is renderable,
199         // because Vulkan will want to do the copy as a draw. All other copies would require a
200         // layout change in Vulkan and we do not change the layout of borrowed images.
201         GrMipMapped mipMapped = willNeedMipMaps ? GrMipMapped::kYes : GrMipMapped::kNo;
202 
203         GrBackendFormat format = proxy->backendFormat().makeTexture2D();
204         if (!format.isValid()) {
205             return nullptr;
206         }
207 
208         sk_sp<GrRenderTargetContext> rtContext(
209             context->contextPriv().makeDeferredRenderTargetContext(
210                 format, SkBackingFit::kExact, info.width(), info.height(),
211                 proxy->config(), nullptr, 1, mipMapped, proxy->origin(), nullptr,
212                 SkBudgeted::kYes));
213 
214         if (!rtContext) {
215             return nullptr;
216         }
217 
218         SkIRect subset = SkIRect::MakeXYWH(origin.fX, origin.fY, info.width(), info.height());
219         if (!rtContext->copy(proxy.get(), subset, SkIPoint::Make(0, 0))) {
220             return nullptr;
221         }
222 
223         return rtContext->asTextureProxyRef();
224     }
225 }
226 
227